1. Field of the Invention
This invention relates to an improved metal building wall liner assembly and to double skin wall constructions employing the liner assembly.
2. Description of the Prior Art
Double skin wall constructions employ profiled sheet metal liner panels which are secured to the structural framework of a building. The liner panels typically are from two feet to five feet wide and are essentially flat except for stiffening beads, if desired. The edges of the liner panels are bent outwardly from the building framework to provide for side-by-side engagement with other liner panels.
The joined edges of the liner panels function as mounting elements for securing an outer facing wall to the building structure. In one form, the outer facing wall comprises parallel facing panels which are secured directly to the assembled liner panels, perpendicularly to the liner panel joints. In another embodiment, subgirt elements are secured perpendicularly to the liner panel joints and facing panels are secured to the subgirt elements. In both embodiments, thermal insulation material is introduced into the space between the liner panels and the facing panels.
A serious shortcoming of the existing double-skin wall construction is that the liner panels are fabricated from sheet steel of uniform thickness. The metal thickness is determined by the requirement for forming connected joint elements to serve as mounting sites in the resulting wall. With increasing requirements for thermal insulation in such double-skin wall constructions, the wall thickness and hence, the side joints of the liner panels must be increased, whereby the web-strength of the joint elements becomes the controlling design limitation and requires even greater steel thickness for the liner panels.
A corollary shortcoming of the existing liner panel construction is that the preponderance of the steel in the liner panels is "ineffective" for design purposes, that is, under the existing design codes, the preponderance of the steel in the liner panels does not contribute to the load carrying capability of the resulting wall assembly.
It is desirable that building components intended for use in wall panel construction are nestable to reduce shipping volume. Many of the liner panels in the prior art are not nestable because of their geometry and therefore require excessive packaging, handling and transportation expenses.
For versatility, it is desirable that liner panels accommodate a variety of different facing panels to permit achieving different architectural appearances in the exterior wall of the resulting building. Thus, it is desirable that liner panels be available in different widths, not only to accommodate different facing panels which might be desired, but also to optimize the structural design of the resulting building.
Building wall panels also should have reliable and simple connecting means to develop an airtight skin for the interior wall surface of the building.